Topics: Radio Program, American composers, Particle physics, National Association of Independent Colleges...

A statistical-stochastic model of the complete life cycle of North Atlantic (NA) tropical cyclones (TCs) is used to examine the relationship between climate and landfall rates along the North American Atlantic and Gulf Coasts. The model draws on archived data of TCs throughout the North Atlantic to estimate landfall rates at high geographic resolution as a function of the ENSO state and one of two different measures of sea surface temperature (SST): 1) SST averaged over the NA subtropics and...

Topics: NASA Technical Reports Server (NTRS), TROPICAL STORMS, CYCLONES, SEA SURFACE TEMPERATURE, SOUTHERN...

The method of averaging is a powerful tool for the integration of systems of ordinary differential equations which have some rapidly oscillating variables and other slowly oscillating variables. This report bridges the gap from casual acquaintance with the underlying idea to technical reading and application. Three examples are worked in detail.

Topics: DTIC Archive, Crockett, Carl E, AIR FORCE ACADEMY COLORADO SPRINGS CO DEPT OF MATHEMATICS,...

This paper concerns Hamiltonian and non-Hamiltonian perturbations of integrable two degree of freedom Hamiltonian systems which contain homoclinic and periodic orbits. Our main example concerns perturbations of the uncoupled system consisting of the simple pendulum and the harmonic oscillator. We show that small coupling perturbations with, possibly, the addition of positive and negative dampling breaks the integrability by introducing horseshoes into the dynamics. (Author)

Topics: DTIC Archive, Holmes,Philip J, CALIFORNIA UNIV BERKELEY CENTER FOR PURE AND APPLIED MATHEMATICS,...

Partial contents of this translation of Chinese reports: A boundary Element Technique in tRAnsonic Flow; EXploariotn of the Spatial Oscillation in Finite Difference Solutions for Navier-Stokes Shock; Calculation of Boundary Layer Growth behind an Unsteady Expansion WAve in A Tube; Numerical Computation for Insiscid Supersonic Flow Arough A Bent Cone; Theory of Similarity and the Profile of the Mean Density Distribution of Hypersonic Boundary Layer; The Engineering Numerical Technique for...

Topics: DTIC Archive, FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH, *BOUNDARY LAYER, *AERODYNAMICS,...

A test to determine the performance differences between the 27-percent-scale models of two rotors for the U.S. Army AH-64 helicopter was conducted in the Langley 14- by 22-Foot Subsonic Tunnel. One rotor, referred to as the baseline rotor, simulated the geometry and dynamic characteristics of the production baseline rotor, and the other rotor, referred to as the advanced rotor, was designed to have improved hover performance. During the performance test, the dynamic pitch-link forces and blade...

Topics: DTIC Archive, Berry,John D, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY...

During the course of this grant algorithms were developed and analyzed for the numerical solution of singularly-perturbed (or stiff) initial value and boundary value problems for ordinary differential equations and initial-boundary value problems for partial differential equations. These general purpose methods have been applied to a wide variety of problems arising in several disciplines, including optimization and optimal control, nonlinear oscillations, chemical reactions, and hydrodynamic...

Topics: DTIC Archive, Flaherty, Joseph E, RENSSELAER POLYTECHNIC INST TROY NY DEPT OF MATHEMATICAL...

An improved theoretical model was developed for interpreting the infrared absorption spectra of doped semiconductors. The model focused on the specific problem of coherent scattering effects or optical channeling. These effects are produced by coherent multiple internal reflections from the polished plane-parallel faces of an optically thin sample. The coherent scattering produces oscillating noise on the infrared absorption spectrum. This noise makes it difficult to determine the correct...

Topics: DTIC Archive, Grigsby, Peggy J, AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH...

High maneuverability is one of the major goals in rotorcraft design. In practice, this goal is limited by unsteady (dynamic) stall near blade leading edges. Studies of three-dimensional boundary layer separation on a rotating blade are made. For hovering flight, the blade twist and downwash are included in the effective angle of attack. For forward flight, high angles of attack are used to simulate the most severe situation at the retreating blade. Because of the disparate scales of the leading...

Topics: DTIC Archive, Blythe, Philip A, LEHIGH UNIV BETHLEHEM PA, *BOUNDARY LAYER, *ROTOR BLADES(ROTARY...

Vibrational sum frequency spectroscopy has been used in conjunction with dynamic surface tension measurements to study formation of a 1,2-dilauroyl-sn- phosphatidylcholine (DLPC) monolayer at a water:carbon tetrachloride interface. Surface tension measurements show that an aqueous solution of liquid crystalline phosphocholine vesicles (4.5 micro Molar DLPC) requires several hours to form a tightly packed, fully equilibrated monolayer of DLPC monomers. Vibrational spectra of the interfacial...

Topics: DTIC Archive, Walker, R. A., OREGON UNIV EUGENE DEPT OF CHEMISTRY, *INTERFACES, *LIQUIDS,...

A flight test program was performed to gain further insight into the phenomenon of flow-induced cavity pressure oscillations and to evaluate the effectiveness of suppression concepts in eliminating or reducing the pressure oscillations. The cavities tested were rectangular with approximate dimensions of 17 inches long, 8.5 inches deep, and 8.75 inches wide and were instrumented with microphones, static pressure ports, and a thermocouple. The flight speeds ranged from Mach number 0.6 to 1.3 at...

Topics: DTIC Archive, Shaw, Leonard L., AIR FORCE FLIGHT DYNAMICS LAB WRIGHT-PATTERSON AFB OH, *AERODYNAMIC...

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Dr. Marcel Vogel discusses how crystals oscillate with the tones of our soul.

Topics: crystals, oscillation, energy, Dr. Marcel Vogel

The Asian southwest monsoon (SWM) east of the Horn of Africa (HOA) is important in planning and conducting maritime operations in this region. Skillful subseasonal to seasonal (S2S) forecasts of the SWM onset are needed for operational planning but are not yet available. We investigated the potential for S2S forecasting of the onset of SWM surface winds and ocean surface waves off HOA by analyzing global atmospheric and oceanic variables, and three onset states: early, normal, and late. We...

Topics: climate, climate variations, climate analysis, long-range forecasting, subseasonal to seasonal,...

We present predictions for the NRL laser/HANE experiment of the effects on an N2 background gas of (1) x-rays emitted following laser irradiation of an aluminum target, (2) debris ions moving out from the target, and (3) deposition of uv radiation resulting from interaction between the debris ions and the background gas. We calculate both primary ionization and time dependent chemistry changes. Results are based on two NRL codes, UVDEP and PRODEP, developed for HANE studies. Certain assumptions...

Topics: DTIC Archive, Hyman,E, NAVAL RESEARCH LAB WASHINGTON DC, *LASER TARGET INTERACTIONS, *NUCLEAR...

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Jun 21, 2010
06/10

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Siljak, D

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Graphical and analytical techniques for calculating regions of absolute stability of linear systems

Topics: GEOMAGNETIC PULSATIONS, MAGNETOHYDRODYNAMIC WAVES, EARTH MAGNETOSPHERE, HARMONIC OSCILLATION,...

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Jul 12, 2010
07/10

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Cooper, L. P

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An advanced orbit transfer vehicles (OTV) which will be an integral part of the national space transportation system to carry men and cargo between low Earth orbit and geosynchronous orbit will perform planetary transfers and deliver large acceleration limited space structures to high Earth orbits is reviewed. The establishment of an advanced propulsion technology base for an OTV for the mid 1990's is outlined. The program supports technology for three unique engine concepts. Work is conducted...

Topics: LATERAL OSCILLATION, ECCENTRICITY, FRICTION FACTOR, GRAPHS (CHARTS), PRESSURE DISTRIBUTION, THRUST...

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May 27, 2011
05/11

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Ray, Richard D.; Bills, Bruce G.; Chao, Benjamin Fon

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A general framework for calculating lunar and solar torques on the oceanic tides is developed in terms of harmonic constituents. Axial torques and their associated angular momentum and earth-rotation variations are deduced from recent satellite-altimeter and satellite-tracking tide solutions. Torques on the prograde components of the tide produce the familiar secular braking of the rotation rate. The estimated secular acceleration is approximately -1300 sec/century(sup 2) (less 4% after...

Topics: TOTAL OZONE MAPPING SPECTROMETER, TROPOSPHERE, ATMOSPHERIC COMPOSITION, TROPICAL REGIONS,...

A study was made to relate theoretically predicted and experimentally observed pressure-coupled combustion instability behavior of solid propellants. Using a generalized theoretical model which incorporates both surface and gas phase combustion effects, the linear and nonlinear (higher pressure amplitude) region has been characterized by a group of combustion parameters. Concurrent experimental studies were directed toward investigating (1) the effects of coating the solid oxidizer crystals,...

Topics: DTIC Archive, Brown, Robert C, UNITED TECHNOLOGY CENTER SUNNYVALE CA RESEARCH AND ADVANCED...

The report presents the results of an experimental investigation of rotor blade dynamic stall. Forces and moments in two-dimensional flow were determined for two thin airfoil sections (NACA 0006 and Vertol 13006-.7) usually considered in advanced helicopter rotor concepts by measuring differential pressure during oscillatory pitch motions. The Mach number, Reynolds number, and angle of attack prevailing in the retreating-blade stall region were investigated up to typical first-torsion mode...

Topics: DTIC Archive, Gray, Lewis, BOEING VERTOL CO PHILADELPHIA PA, *ROTOR BLADES(ROTARY WINGS),...

Measurements of the unsteady forces on heaving delta wing hydrofoils hydrofoils having apex angles of 15 and 30 deg were carried out in fully wetted flow, planing at a free surface, and with forced ventilation. The fully wetted dynamic measurements were in good agreement with the results of lifting surface theory at small angles of attack. A slender body theory of planing due originally to Tulin is extended to account for non-steady motions. This theory generally underestimates the in-phase...

Topics: DTIC Archive, DeLong, Raymond K, CALIFORNIA INST OF TECH PASADENA DIV OF ENGINEERING AND APPLIED...

Temperatures in the range of 2500 to 5000K were measured in the seeded air and nitrogen plasmas produced with a 2 megawatt arc heater. Two specially designed spectra probes were used for these measurements. Mass seed rates of potassium carbonate ranged from 0 to 1.88% by weight of potassium and power levels ranged from 300 kw to 1000 kw. Temperatures determined from measured intensities of the continuous radiation and from atomic spectral lines of potassium were found in the seeded plasmas to...

Topics: DTIC Archive, Olsen, H N, PLASMA SCIENCES LABS INC VAN NUYS CA, *PLASMA JETS, ABSORPTION, AIR,...

The evolution of forces acting on horizontal cylinders subjected to impact by an harmonically oscillating free surface has been investigated both theoretically and experimentally. The experiments were carried out in a large U-shaped water tunnel, with cylinder diameters ranging from 3.0 to 6.5 inches. The results have been expressed in terms of two force coefficients. The first is the slamming coefficient which expresses the normalized force acting on the cylinder at the time of impact; and the...

Topics: DTIC Archive, Post,Richard A, NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF, *WATER WAVES, *IMPACT...

A method for the analysis of perturbations of integrable planar systems of differential equations is developed. Concentrating on the case in which the unperturbed system is Hamiltonian and the perturbation introduces dissipation and time-periodic forcing, the global solution curves of the unperturbed system are used in regular perturbation calculations to locate subharmonic orbits and homoclinic orbits and to characterize the bifurcations in which they are created as external parameters are...

Topics: DTIC Archive, Greenspan, Bernie D, CALIFORNIA UNIV BERKELEY CENTER FOR PURE AND APPLIED...

The forces acting on yawed smooth and rough circular cylinders in oscillating flow have been investigated for the purpose of determining the appropriate force-transfer coefficients and the applicability of the 'independence principle.' The results have shown that the flow about each cylinder is unique and the independence principle does not hold true over the range of Reynolds numbers and Keulegan-Carpenter numbers covered by the investigation. It has further been shown that Morison's equation...

Topics: DTIC Archive, Sarpkaya,Turgut, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *YAW, *CYLINDRICAL BODIES,...

Partial Contents: Vehicle-Structure Interactions in Bridge Dynamics; Literature Review--Vibration of overhead transmission lines Part 4; Abstracts from the Current Literature; and Annual Indexes.

Topics: DTIC Archive, Eshleman, R L, NAVAL RESEARCH LAB WASHINGTON DC SHOCK AND VIBRATION INFORMATION...

The Ports of Los Angeles and Long Beach have shown continual patterns of growth in commerce which require the planning for additional harbor basins, ship-mooring facilities, and the dredging of deeper channels to accommodate this expansion. To achieve a successful plan for harbor growth it is necessary to investigate, among other factors, the effect a plan will have on tidal flushing of the harbor area and on harbor resonance, where long-period harbor oscillations are important with regard to...

Topics: DTIC Archive, Seabergh,W C, COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS, *GROWTH(GENERAL),...

During the testing there were no observed changes in the lateral control characteristics of the U-21A. No tendency for aileron oscillation, buffet or feedback into the U-21A control system was noted. At airspeeds above 150 KCAS the 1/4 inch diameter antenna sensors vibrated approximately + or - one diameter and were bowed aft approximately 2 diameters from their static position. The lateral control pulses or steps did not cause any further excitation of the 1/4 inch antenna. Within the scope of...

Topics: DTIC Archive, Mittag,Carl F, ARMY AVIATION ENGINEERING FLIGHT ACTIVITY EDWARDS AFB CA, *AIRCRAFT...

This work consisted of an extensive series of experiments with ship models that were either fixed or moored in a current in shallow water. The experiments were designed to shed light on apparent contradictions in published data on the hydrodynamic force coefficients and to provide data for two ships moored side by side. The objectives of Phase I, which experiments with a single model, were to test the effect of the Reynolds number, define the effect of the width of the flume, and investigate...

Topics: DTIC Archive, DANISH HYDRAULIC INST HOERSHOLM, *SHIP MOTION, *MOORING, SHIPS, WATER FLOW, TIME...

The force testing of small scale models in either a small wind tunnel or a water tunnel was investigated as an inexpensive and quick means to obtain meaningful dynamic force and moment data representative of rapidly maneuvering full-scale aircraft. Force tests of flat-plate semi-span models were conducted in the General Dynamics Aerodynamic Development Facility (ADF) which is a small 14x14 sq in. low speed wind tunnel. Oscillatory model motions up to 48 deg (peak to peak) amplitude were tested...

Topics: DTIC Archive, Cunningham, Jr , Atlee M, GENERAL DYNAMICS FORT WORTH TX FORT WORTH DIV,...

Line asymmetries and wavelength shifts can be produced by dynamical processes at work in the solar photosphere. Dravins, Nordlund and coworkers (ref. 1, 2, 3) discussed the importance of the granulation in determining the C- shape of solar lines of Fe I and Fe II ions. Iron is a suitable atomic species to diagnose photospheric motions, since it has negligible asymmetries due to isotope composition and to pressure shifts and no hyperfine structure splitting. Marmolino, Roberti, Severino and...

Topics: DTIC Archive, Marmolino, C, AIR FORCE SYSTEMS COMMAND HANSCOM AFB MA GEOPHYSICS LAB, *SOLAR...

Close to the onset of self-excited fluid oscillations the generic complex Ginzburg-Landau is proposed as the lowest order model for the plant. Its linear part which provides the stability boundaries is derived from first principles for both doubly-infinite and semi-infinite flow domains. Concentrating on a single global mode, the model is further simplified to the Stuart-Landau equation. For this latter model a methodology is developed for the design of single-input single-output controllers....

Topics: DTIC Archive, Monkewitz, Peter A, CALIFORNIA UNIV LOS ANGELES SCHOOL OF ENGINEERING AND APPLIED...

Numerical computations are reported for a spike-nosed projectile configuration with a vortex generator ring. A new vortex-dominated flow field is computed at supersonic speeds of M - 3.5, 3.0, and 1.9. A time-dependent Navier- Stokes computational technique with a zonal gridding was used. The axial force at zero angle of attack was computed and found to be in good agreement with the wind tunnel data at Mach 3.0. The sting quantitative effect on the axial force coefficient and the flow pattern...

Topics: DTIC Archive, Mikhail, Ameer G, ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD, *PROJECTILES,...

The tumbling motion of aerodynamically stable bodies entering planetary atmospheres is analyzed considering that the tumbling, its arrest, and the subsequent oscillatory motion are governed by the equation for the fifth Painleve' transcendent. Results based on the asymptotic behavior of the transcendent are applied to study (1) the oscillatory behavior of planetary probe vehicles in relation to aerodynamic heating and loads and (2) the dynamic behavior of the Australian tektites on entering the...

Topics: DTIC Archive, Tobak, Murray, NATIONAL AERONAUTICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES...

Parasitic oscillationsmult and intermodulation products occurring in HF multicouplers used at large antenna array sites are measured and analyzed. Both on-site and laboratory data are used to illustrate the signature of these undesirable signals which are readily analyzed using a 3-axis (time vs. frequency) display. Conclusions and recommendations are offered.

Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *INTERMODULATION, *ANTENNA ARRAYS, LABORATORY...

The direct current produced from the Van de Graaff (VDG) at the Air Force Research Laboratory (AFRL) has been measured and analyzed. The current pulse produced from the VDG is oscillatory. Experimental data show complete damping occurs after 8 oscillations and within 10-6 seconds. The spark gap distance and circuit resistance were varied to determine if the circuit could convert to an overdamped RLC circuit in order to reduce the oscillations. The data establishes that the VDG produces at least...

Topics: DTIC Archive, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND...

The rapid variable star, Epsilon Per (B0.5 IV-III), displays the largest amplitude profile fluctuations known among the growing number of massive, spectrum-variable stars. Here we present an analysis of a continuous 5 day run of IUE UV spectroscopy, and we show for the first time that the systematic, blue-to-red moving patterns observed in high-quality optical spectra are also present in the UV photospheric lines. We present cross-correlation functions of the individual spectra with that of a...

Topics: DTIC Archive, NAVAL OBSERVATORY WASHINGTON DC, *VARIABLE STARS, CROSS CORRELATION, OSCILLATION,...

An experimental investigation into rotor blade dynamic stall was conducted. Two typical airfoils, the NACA 0012 (modified) and the Vertol 23010- 1.58, were tested by measuring the differential pressures acting during pitching and translatory oscillations over a range of angles of attack covering the stall regime. There were two main objectives. The first was to determine the influence of stall on the aerodynamic pitching moment of an airfoil executing pitching motions corresponding to the...

Topics: DTIC Archive, Liiva, Jaan, BOEING VERTOL CO PHILADELPHIA PA, *HELICOPTERS, *ROTOR BLADES(ROTARY...

The report presents a discussion of the test facility, models, and data gathering and reduction system used in the tests of oscillating airfoils. It also contains the actual computer data that resulted from the wind tunnel tests of the airfoils. A set of tables provides a quick cross-reference between the various test factors and the page on which the data appear.

Topics: DTIC Archive, Gray, Lewis, BOEING VERTOL CO PHILADELPHIA PA, *HELICOPTERS, *ROTOR BLADES(ROTARY...

Topics: DTIC Archive, Belousov,B N, FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO, *BOUNDARY VALUE...

The United States Army Aviation Engineering Flight Activity conducted a limited airworthiness flight evaluation of an NUH-1H helicopter in which a prototype global positioning system (GPS) was installed. Flight tests were conducted at Edwards Air Force Base, California, between 18 and 27 January 1977. Nine test flights were conducted for a total of 11 productive flight hours. Testing was performed to determine the effect of GPS installation on vibration and pilot-induced oscillation (PIO)...

Topics: DTIC Archive, Thomas,Charles L, ARMY AVIATION ENGINEERING FLIGHT ACTIVITY EDWARDS AFB CALIF,...

Source-free Maxwell equations are derived for n electromagnetic (carrier) wave in an inhomogeneous medium exhibiting nonstationary linear response. The non-stationarity is assumed to be slow in comparison with the carrier oscillation, and the equations that result assume that time-derivatives of all slowly varying quantities higher than the first order can be neglected. The equations form the theoretical basis of analysis of the nonlinear dynamics of the coupling of laser energy into a fluid,...

Topics: DTIC Archive, Cawley,R, NAVAL SURFACE WEAPONS CENTER SILVER SPRING MD, *ELECTROMAGNETIC WAVE...

This paper introduces methods tailored especially for problems whose solution behave like sub lambda x, ch1, where lambda is complex. The shallow water equations with topography admit such solution. This paper complements the results of Pratt and others on exponential-fitted methods and those of Gautschi, Neta, van der Houwen and others on trigonometrically-fitted methods.

Topics: DTIC Archive, Neta,Beny, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *EXPONENTIAL FUNCTIONS, *FITTING...

During the past two years, we have been able to understand, in principle, the mechanism of one predominant mode of combustion instability in dump combustors for ramjet engines. The objectives of further experiments have been to provide a quantitive, physical basis for elements of this mechanism which will allow application of the results to a wide class of combustor sizes, fuels and mixture ratios, and to more complex acoustic environments. One mode of unsteady combustion in dump burners, which...

Topics: DTIC Archive, Marble,Frank E, CALIFORNIA INST OF TECH PASADENA, *COMBUSTORS, *RAMJET ENGINES,...

An experimental and theoretical investigation was conducted to study the wick combustion of Lithium and Sulfur hexafluoride. A single-line laser induced fluorescence thermometry with Li2 as fluorescence species was developed. The calibration experiments yielded promising results; refinements, however, are needed before the technique can be applied to combustion flame measurements. Wick combustion of ethanol and hexane in air as well as Li and SF6 was conducted in a vacuum chamber at atmospheric...

Topics: DTIC Archive, Chen, L D, IOWA UNIV IOWA CITY DEPT OF MECHANICAL ENGINEERING, *ETHANOLS, *SULFUR...

Basic results were obtained and published on the mathematical characterization of feed-forward and recurrent neural networks. It was shown how to approximate any continuous function by a 3-layer feed-forward network. The fixed-points and oscillations of recurrent networks were analyzed. Neural networks, dynamical systems.

Topics: DTIC Archive, Blum, Edward K, UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF MATHEMATICS,...

In 1947, Willis Winslow was awarded a U.S. patent on 'Methods and Means for Translating Electrical Impulse Into Mechanical Forces'. Winslow's patent makes use of an electrorheological (ER) fluid, i.e., one which is transformed from a liquid into a viscoelastic solid upon application of a strong electric field. Based on this gelation effect, a whole new technology has been proposed, providing novel and efficient ways to control fluid flow and power transmission, and to reduce energy loss and...

Topics: DTIC Archive, Krieger, Irvin M, CONSULTEC SCIENTIFIC INC KNOXVILLE TN, *ELECTRIC FIELDS, *RHEOLOGY,...

Time and depth varying cross shore currents forced by gravity and infragravity waves in the nearshore are numerically modeled. Model evaluation is made with analytical solutions and laboratory data. Cross shore flow is simulated with two linked models: a depth integrated model and an eigenfunction solution for velocity distribution over depth. Water surface gradients generated by the depth integrated model are used to drive the profile model. Both models are time dependent. Two numerical...

Topics: DTIC Archive, Smith, Jane M., DELAWARE UNIV NEWARK CENTER FOR APPLIED COASTAL RESEARCH, *OCEAN...

Divergent cusped-field thrusters are electric propulsion devices characterized by a divergent, dielectric wall channel and a magnetic topology dominated by two magnetic cusps and a magnetic bottle near the anode. Initial testing results suggest that this technology may lend itself to miniaturization while providing improved lifetime performance over miniature Hall thruster designs. This paper presents results of detailed probing of the divergent cusped-field thruster plume using a faraday cup...

Topics: DTIC Archive, AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE, *PLUMES, *PLASMA...

Noise characteristics in shock-containing jets at an overexpanded jet condition have been investigated. Total temperature ratios of 1.0 (cold), 2.0, and 3.0 are considered. The cold jet is a highly screeching jet. Frequency-wavenumber Fourier analysis is employed to examine the wave characteristics of pressure waves along the lip line and also along a near-field conical surface. It is found that the radiating portion of the pressure wave intensity increases with the jet temperature, but the...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *JET ENGINE NOISE, *JET FLOW, *NUMERICAL ANALYSIS,...

Topics: DTIC Archive, SWERLING, P, RAND CORP SANTA MONICA CA, *RADAR TARGETS, DETECTION, OSCILLATION,...